docs: def catalogue_mt_filter(self, mt_table, flag=None):
          """
          Filter the catalogue using a magnitude-time table. The table has
          two columns and n-rows.
  
          :param nump.ndarray mt_table:
              Magnitude time table with n-rows where column 1 is year and column
              2 is magnitude
  
          """
          if flag is None:
              # No flag defined, therefore all events are initially valid
              flag = np.ones(self.get_number_events(), dtype=bool)
  
          for comp_val in mt_table:
              id0 = np.logical_and(self.data['year'].astype(float) < comp_val[0],
                                   self.data['magnitude'] < comp_val[1])
              print(id0)
              flag[id0] = False
          if not np.all(flag):
              self.purge_catalogue(flag)